Renal colic is pain caused by a urinary tract stone (urolithiasis). The pain can be anywhere in the urinary tract, which includes the area from the kidneys to the ureters, urinary bladder, and urethra.
Stones can occur anywhere in these areas and can vary significantly in size. Most stones occur due to a buildup of minerals or other substances, such as uric acid, which stick together in the urine, creating a hard mass.
There are many treatment options for urinary stones. Many stones pass without surgical intervention, making managing renal colic a primary concern during treatment.
Symptoms of renal colic can vary based on the size of the stone and its location in the urinary tract. Some small stones cause only mild renal colic, and a person may pass them in the urine without much discomfort.
Larger stones can cause excruciating pain, especially if they get stuck and block any small points in the urinary tract, such as where it meets the kidney or urinary bladder, or the ureter — the tube through which the urine passes between the kidney and the bladder.
The most common presentation of renal colic is pain that occurs on the affected side of the body between the lower ribs and hip that radiates to the lower abdomen and groin.
The pain tends to come in waves that can last from 20 to 60 minutes before subsiding until the next wave.
Renal colic is just one of the symptoms caused by urinary stones. Other symptoms that typically occur alongside renal colic include:
- pain or difficulty urinating
- blood in the urine which may give it a pinkish, red, or brown color
- foul-smelling urine
- small particles in the urine
- feeling a constant urgent need to urinate
- cloudy urine
- urinating more or less than normal
Anyone experiencing the following symptoms in addition to renal colic should contact emergency medical services immediately:
- complete inability to urinate
- uncontrollable vomiting
- a fever over 101°F
Renal colic is caused by a stone getting stuck in the urinary tract. This commonly occurs in a ureter, where the stone stretches the surrounding area of tissue while trying to pass through; inflammation and pressure from urine flow restriction may also occur.
The ureter may also spasm. This situation is painful, as the ureter is not meant to have stones inside of it.
Urinary stones can be made up of numerous chemicals and minerals caused by a few different risk factors. Risk factors for developing a urinary stone include:
Doctors will often use blood tests to check for increased levels of stone-forming substances in a person's body. An imaging test such as a plain film X-ray, a computed tomography (CT) scan, or ultrasound can help locate any significant stones in the urinary tract.
Medical treatment will often depend on the type of stone a person is experiencing. There are some different types of stones, including:
- Calcium stones are the most common types of stones and are made up of calcium oxalate
- Uric acid stones develop when uric acid concentrates in the urine
- Cystine stones are rare and are caused by the disorder cystinuria
- Struvite stones are less common stones caused by certain bacteria in the urinary tract
Most small stones are considered passable. In fact, up to 80 percent of stones will pass out of the body in the urine. Doctors will recommend proper hydration and may prescribe pain-relieving medications to help deal with the pain while monitoring the stone until it passes.
There is a range of procedures to help remove larger stones and relieve renal colic. These include:
- Ureteroscopy guided stone extraction: This is an invasive surgical procedure where a doctor inserts a thin scope with a light and camera on it into the urinary tract to locate the stone and remove it.
- Extracorporeal shock wave lithotripsy (ESWL): A noninvasive treatment, ESWL is the process of aiming small soundwaves at the kidneys to break up stones into tiny pieces. These fragments are then passed in the urine.
- Percutaneous nephrolithotomy: Percutaneous nephrolithotomy is typically done under general anesthesia. It is the process of entering the kidney through a small cut in the back and using a lighted scope and small instruments to remove the stone.
- Stent placement: Sometimes, doctors will place a thin tube into a person's ureter to help relieve the obstruction and promote the passing of stones.
- Open surgery: Some people who cannot pass the stones may require open surgery, but it has a longer recovery time. Doctors will often try to extract or break up the stones so a person can pass them before considering open surgery.
Treatment may also include medications designed to help relieve symptoms or reduce the accumulation of stones. These treatments may include:
- alkalinizing agents
- calcium channel blockers
- selective alpha-1 blockers
Pain management is an essential step in treatment, as it can increase a person's quality of life until the stone passes. While a person is still dealing with symptoms, doctors may also recommend medications to calm the GI tract and manage any nausea and vomiting.
Some people may also respond to placing a heat pack on their side or lower back, as it may calm the muscle spasms associated with renal colic.
Avoiding renal colic starts with preventing the stones that caused it. Doctors may recommend that a person increases their fluid intake and reduces their sodium intake.
A doctor may prescribe a thiazide diuretic if a person has calcium oxalate urinary tract stones. While drinking more fluid may or may not improve renal colic or help flush stones out of the urinary tract, it will at least prevent dehydration.
Many people also benefit from eating a healthful diet rich in a variety of whole grains, vegetables, fruits, and lean proteins. Doctors may also recommend increasing the intake of citrus fruits in the diet, such as oranges, lemons, or grapefruits.
Many stones will pass on their own, but may still result in renal colic. Doctors will often explore the best combination of both medical and surgical treatment options to help break down larger stones and let them pass.
It is possible for stones in the urinary tract to happen again after successful treatment. Taking preventative measures can help avoid developing stones in the future and reduce symptoms of renal colic.